4
votes
Switching mix of Ethernet speeds?
Shared memory and port buffering are not mutually exclusive:
Packets payloads will be stored in shared memory prior to being transmitted (think how inefficient it would be to store a broadcast frame ...
- 9,156
4
votes
Accepted
Switching mix of Ethernet speeds?
If the frames entering the switch are using a 1G port, but are being forwarded out a 100M port, then it's likely that frames are coming in faster than they are going out. So they need to be buffered ...
- 66.1k
4
votes
Why is MPLS label added between layer 2 header and layer 3 header of OSI model and not between headers of layer 3 and 4 of OSI model?
MPLS is a layer-2 protocol. However, no layer-1 carries MPLS directly, so it gets tacked on to various other layer-2 protocols. (hence "layer-2.5") Adding it after a layer-3 header would ...
- 31.1k
3
votes
Tagged frames onto untagged (access) port!
This question has been asked at least a dozen times.
We can only guess why the spec says what it says -- no one here wrote it.
Despite what the spec says, no one does that -- "ingress filtering" is ...
- 31.1k
3
votes
Switch Fabric Capacity vs Forwarding Rate
What is the difference between Switch Fabric Capacity and Forwarding Rate of a switch?
Switch Fabric Capacity: It usually means the maximum rate the hardware can move information between cards/ports. ...
- 1,636
2
votes
Accepted
Switch Fabric Capacity vs Forwarding Rate
Remember that what you are looking at is marketing material.
The Switch Fabric Capacity is listed in bits per second (bps) and is usually double what it really does since the vendors count full ...
- 97.7k
2
votes
Accepted
Full and half duplex 100 Mbs on the same switch
In a hub, all the ports are electrically connected, and only one device at a time can talk on the wire. If more then one device talks at the same time, it creates a collision, so hub ports are all ...
- 97.7k
2
votes
Full and half duplex 100 Mbs on the same switch
The mode/speed is configured on the switch port! So you could have 12 ports in half-duplex(for devices that don't support full-duplex) and 12 ports in full-duplex. On the assumption that you're on a ...
- 209
2
votes
Broadcasting in L2 Switch
A broadcast frame is forwarded to all switch ports but the one it was received from. When several switches are connected to each other the broadcast will eventually reach all ports in this broadcast ...
- 79.8k
2
votes
Connecting two switches with an access mode port
You don't mention brand of the switch, any management software, or any configuration (in particular how that interface was previously configured), so I can only answer generically.
Most default ...
- 27.1k
2
votes
Why Switching Modes and when to use one of the other?
This is a lot more complex than just a software-selectable forwarding option - and is true not only for Cisco but most other vendors.
First of all - store-and-forward vs cut-through generally isn't ...
- 6,094
2
votes
Accepted
How many PoE ports can I use on a switch?
It rather depends on what is real. 24V 6.5W is not 24V 0.5 A - but I think the latter number is just what the default (passive) POE power brick is, and they are oversized somewhat by default.
24V 0....
- 2,746
2
votes
How many PoE ports can I use on a switch?
I don't know the exact model you are using, but the specs I read say 48V @.5A. That's 24 watts (and is more inline with similar APs)
23 ports @ 24W = 552 Watts. So, no, you can't power all the ...
- 66.1k
2
votes
Inter-VLAN Routing
Configure each VLAN with "no shutdown." Make sure that the VLANs are active. "Conf t" and the type "vlan 2" and see if that brings the VLAN up. Do this with the rest of the VLANs.
Make sure that each ...
2
votes
dhcp client not receving the ip address using two switches
On switch 2, the client ports are on VLAN 100 and 200 (not 10 and 20).
EDITED to include Marc Luethi's comment:
On ESW2, the switchports where R1, R2, R3 are connected are without
spanning-tree ...
- 66.1k
2
votes
Accepted
Non [R]STP switches in LAN ring topology
If you plan to create a ring of switches, all those switches need to support RSTP or MSTP.
That is, unless all the unmanaged switches completely ignore IEEE 802.1D and actually forward the RSTP BPDUs -...
- 79.8k
2
votes
What are the Major Differences between Juniper EX4200 vs Juniper EX4300?
EX4300s have four QSFP+ ports (rear panel) which may be used for stacking or as 40GbE. They also don't require an uplink module (EX-UM-xxx) and therefore have four SFP+ 1/10G ports (front panel) in ...
- 5,374
2
votes
Accepted
What are the Major Differences between Juniper EX4200 vs Juniper EX4300?
If you're looking at purchasing new hardware, EX4300s are generally recommended. It's not that there's anything wrong with the EX4200, it's simply that the EX4300 is the next generation with new ...
- 6,925
2
votes
Accepted
Message switching vs packet switching with respect to congestion traffic
This seems to assume that queues can have limited number of packets (true enough), but unlimited packet size (not true). The idea that a large message packet size uses fewer places in the queue is ...
- 97.7k
1
vote
Accepted
cut-through vs store-and-forward switching
We assume that [...] the delay inside the switches is 0. [...] We should have an end-to-end delay equal to 1 x transmission time according to the same reference.
The "delay inside the switches&...
- 79.8k
1
vote
How to reset a Default username and password of Allied Telesis AT9000/28 switch using CLI?
I would defy the purpose - securing management access - if you could reset the credentials via console.
As it seems, AT has made no provisions to reset the password by physical reset switch either. ...
- 79.8k
1
vote
Can anyone please explain L3 SVI configuration ,What is SVI and Where do we use it?
On Cisco devices, SVI's are configured just like a physical interface. They are named for the vlan they're attached to.
For example, the SVI for Vlan 10 is named interface vlan10. To assign an IPv4 ...
- 66.1k
1
vote
Can anyone please explain L3 SVI configuration ,What is SVI and Where do we use it?
An SVI is a Switched Virtual Interface. It is an interface for the VLAN itself on the switch. It can be a layer-3 interface (IP addressing) to allow the switch itself to participate in the VLAN.
A ...
- 97.7k
1
vote
Sending tagged traffic to untagged port?
An access port that receives tagged traffic will drop the tagged frames.
- 66.1k
1
vote
Inter-VLAN Routing
You still need to configure the VLAN 3 SVI on the L3 switch.
You also need to set trunk mode and encapsulation on Fa0/24 of all three L2 switches.
- 476
1
vote
Can't establish the connection for switch
Your problem is that the VTP passwords don't match.
On the non-working switch:
MD5 digest : 0xB9 0x07 0xEE 0xE3 0x27 0xEC 0xF7 0x33
0x98 ...
- 97.7k
1
vote
How does message switching compare with other switching techniques?
A message could be circuit switched or packet switched. You would probably classify message switching as an application layer construct.
Packet switching can break a large message into smaller ...
- 97.7k
1
vote
About the switchport mode
Specifically concerning negotiate or nonegotiate ...
By default, the negotiation port setting is on, that is , the ability to negotiate a trunk port (if not a trunk the port becomes an access port.) ...
- 43
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